Method and apparatus for processing an ore feed

Abstract

A sizing roller screen apparatus and method for processing an ore feed received at an inlet is disclosed. The ore feed includes sized ore portions and oversize ore portions. The apparatus includes a roller screen having a plurality of adjacent screening rollers supported to provide interstices therebetween for permitting passage of the sized ore portions between the adjacent screening rollers, the adjacent screening rollers being operably configured to rotate to cause a first sized ore portion to pass through the interstices while the ore feed is being transported along the roller screen. The apparatus also includes a sizing roller disposed generally above an opposing one of the plurality of adjacent screening rollers, the sizing roller being operably configured to rotate to fragment at least some of the oversize ore portions passing between the sizing roller and the opposing screening roller to produce a second sized ore portion, the second sized ore portion being sized for passage between the interstices.

1. A sizing roller screen apparatus for processing an ore feed received at an inlet, the ore feed including sized ore portions and oversize ore portions, the apparatus comprising:
 a roller screen having a plurality of adjacent screening rollers extending away from the inlet and supported to provide interstices therebetween for permitting passage of the sized ore portions between the adjacent screening rollers, the adjacent screening rollers being operably configured to rotate to cause a first sized ore portion to pass through the interstices while the ore feed is being transported along the roller screen away from the inlet; and 
 a sizing roller disposed generally above an opposing one of the plurality of adjacent screening rollers, the sizing roller being operably configured to rotate to fragment at least some of the oversize ore portions that are transported along the roller screen and pass between the sizing roller and the opposing screening roller to produce a second sized ore portion, the second sized ore portion being sized for passage through the interstices. 
 
     
     
       2. The apparatus of  claim 1  wherein at least some of the screening rollers comprise a plurality of spaced apart generally circular plates supported on a shaft, the plates arranged along the shaft to intermesh with spaced apart plates of an adjacent screening roller to provide the interstices. 
     
     
       3. The apparatus of  claim 2  wherein the sizing roller comprises a plurality of generally circular spaced apart plates supported on a shaft, the plates arranged along the shaft to intermesh with spaced apart plates of the opposing screening roller. 
     
     
       4. The apparatus of  claim 3  wherein the opposing screening roller is spaced apart from the adjacent screening rollers and wherein the roller screen further comprises a plurality of static plates extending between the opposing screening roller and an adjacent screening roller and intermeshing therewith, the static plates being sufficiently spaced apart to permit the sized ore portions to pass between the static plates. 
     
     
       5. The apparatus of  claim 1  wherein the sizing roller defines an outer working surface that is sufficiently spaced apart from an outer working surface of the opposing screening roller to permit at least some of the oversized ore portions to be fragmented to produce the second sized ore portion. 
     
     
       6. The apparatus of  claim 5  wherein the outer working surface of the sizing roller comprises a wear resistant overlay for reducing abrasion of the sizing roller by the ore feed. 
     
     
       7. The apparatus of  claim 5  wherein the outer working surface of the sizing roller is spaced apart from the outer working surface of the opposing screening roller in proportion to a spacing between outer working surfaces of the plurality of adjacent screening rollers. 
     
     
       8. The apparatus of  claim 5  wherein the outer working surface of the sizing roller is spaced apart from the outer working surface of the opposing screening roller by about 50 mm to about 60 mm. 
     
     
       9. The apparatus of  claim 5  wherein the outer working surface of the sizing roller comprises first engagement means for engaging the oversized ore portion and forcing the oversized ore portion against the outer working surface of the one of the plurality of adjacent screening rollers to cause the oversized ore portion to be fragmented to produce the second sized ore portion. 
     
     
       10. The apparatus of  claim 9  wherein the outer working surface of the opposing screening roller comprises second engagement means for engaging the oversized ore portion and forcing the oversized ore portion against the outer working surface of the sizing roller to cause the oversized ore portion to be fragmented to produce the second sized ore portion. 
     
     
       11. The apparatus of  claim 10  wherein the first engagement means and the second engagement means comprise respective first and second engagement features that intermesh with each other to fragment the oversized ore portion. 
     
     
       12. The apparatus of  claim 1  wherein the sizing roller comprises a compliant mounting operably configured to permit the sizing roller to be displaced away from the opposing screening roller when oversize ore that resists fragmentation is passed between the sizing roller and the opposing screening roller. 
     
     
       13. The apparatus of  claim 12  wherein the adjacent screening rollers are supported in a first frame and the sizing roller is mounted in a second frame disposed above the first frame, and wherein the compliant mounting comprises a pivot between the first and second frames, the pivot being operably configured to permit the second frame to displace away from the opposing screening roller. 
     
     
       14. The apparatus of  claim 1  wherein the roller screen comprises a discharge outlet located distally along the roller screen from the inlet, the outlet being operably configured to discharge the oversize ore that resists fragmentation. 
     
     
       15. The apparatus of  claim 14  further comprising a comminutor located to receive the oversize ore from the outlet, the comminutor being operably configured to fragment the oversize ore to provide a third sized ore portion. 
     
     
       16. The apparatus of  claim 1  further comprising a variable speed drive coupled to each of the adjacent screening rollers and the sizing roller, the variable speed drive being operable to permit configuration of respective rotational speeds of each of the rollers for processing the ore feed. 
     
     
       17. The apparatus of  claim 1  wherein the ore feed comprises a bitumen portion, and further comprising at least one nozzle disposed to spray heated water onto the ore feed to cause the bitumen portion to become less viscous thereby aiding in the processing of the ore feed. 
     
     
       18. The apparatus of  claim 17  wherein the at least one nozzle comprises a plurality of nozzles located along an entire length of the roller screen and operably configured to spray heated water onto the ore feed as the ore feed moves along the roller screen. 
     
     
       19. The apparatus of  claim 1  wherein the roller screen is disposed above a slurry vessel operable to produce a bitumen ore slurry of the sized ore that passes through the roller screen. 
     
     
       20. The apparatus of  claim 1  wherein the opposing screening roller comprises a generally centrally located one of the plurality of adjacent screening rollers. 
     
     
       21. The apparatus of  claim 1  wherein the plurality of adjacent screening rollers comprise first, second, third, fourth and fifth adjacent screening rollers, and the opposing screening roller is the third adjacent roller. 
     
     
       22. A sizing roller screen apparatus for processing an ore feed received at an inlet, the ore feed comprising a bitumen portion and including sized ore portions and oversize ore portions, the apparatus comprising:
 a roller screen having a plurality of adjacent screening rollers supported to provide interstices therebetween for permitting passage of the sized ore portions between the adjacent screening rollers, the adjacent screening rollers being operably configured to rotate to cause a first sized ore portion to pass through the interstices while the ore feed is being transported along the roller screen; 
 a sizing roller disposed generally above an opposing one of the plurality of adjacent screening rollers, the sizing roller being operably configured to rotate to fragment at least some of the oversize ore portions passing between the sizing roller and the opposing screening roller to produce a second sized ore portion, the second sized ore portion being sized for passage through the interstices; and 
 at least one nozzle disposed to spray heated water onto the ore feed to cause the bitumen portion to become less viscous thereby aiding in the processing the ore feed. 
 
     
     
       23. The apparatus of  claim 22  wherein the at least one nozzle comprises a plurality of nozzles located along an entire length of the roller screen and operably configured to spray heated water onto the ore feed as the ore feed moves along the roller screen.